1. Field of the Invention
The present invention generally relates to a process for the preparation of trifluoroiodomethane (CF3I) by the reaction of trifluoromethane (CF3H) and iodine (I2) in the presence of new catalyst promoters employed in the presence or absence of oxygen. More particularly; the present invention relates to catalyst promoters for the direct synthesis of trifluoroiodomethane (CF3I) from the reaction of trifluoromethane (CF3H) with iodine (I2) in the presence or absence of oxygen.
2. Description of the Related Art
Trifluoroiodomethane (CF3I) is a potential fire extinguishing agent that can be used as a substitute for Halon 1301 (CBrF3) and Halon 1211 (CBrClF2), which are ozone-depleting substances. It is also a potential refrigerant with a low global warming effect.
Trifluoroiodomethane has heretofore been produced by reacting trifluoromethane (CF3H) with iodine in the presence or absence of oxygen using conventional iodination catalysts. U.S. Pat. No. 5,892,136 (1999) to Nagasaki et al. and Japanese Patent No. JP 52-68110 (1977) to N. Nomura describe methods for producing trifluoroiodomethane. Japanese Patent No. JP 2005-8453 (2005) to Nagasaki et al. describes a method and apparatus for producing trifluoroiodomethane. An article by Nagasaki et al. in Catal. Today, 88, pages 121-126 (2004), provides a study on a novel catalytic reaction and its mechanism for CF3I synthesis. Another article by Nagasaki et al. in Proceedings of the Halon Options Technical Working Conference, Albuquerque, N. Mex., 2000, pp. 180-185 provides a description of the development of a novel catalytic technology for CF3I manufacture. Still another article by N. Nagasaki in Specialty Chemicals Magazine, June 2002, pp. 31-32 provides a description of a novel catalytic technology for the manufacture of CF3I. French Patent No. FR 2,794,456 (2000) to Jean Marc Sage describes a process for producing trifluoroiodomethane, pentafluoroiodoethane (i.e., pentafluoromethyl iodide) or a mixture thereof.
It would be desirable to have an improved process for the preparation of CF3I by the reaction of trifluoromethane and iodine.